Bridge



(No Model.)

W. S. BRELSPOARD.

BRIDGE.

110. 531,768. Patented Jan, 1, 1895.

UNITED STATES PATENT IVILLIAM S. BRELSFOARD, 0F JACKSONBURG, OHIO.

BRIDGE.

SPECIFICATION forming part of Letters Patent No. 531,768, dated January1, 1895.

Application iiled lune 30, 1894. Serial No.'516,l68. (No model.)

To all whom t may concern:

Be it known that I, WILLIAM S. Bimes- FOARD, of .Iacksonburg, Butlercounty, Ohio, have invented certain new and useful Im` provements inBridges, of which the following is a specitication.

My invention relates to that class ot' bridges wherein the roadway issupported by side trusses, and the objects of my improvement areembodied in the form of construction and manner of adjusting the trussesand in the manner of supporting them on the abutments. These objects areattained in the following described manner as illustrated in theaccompanying drawings, in which-` Figure l is a side elevation of thebridge: Fig. 2, the portion of a transverse vertical section thereof,and Fig. 3 au enlarged perspective view of one ot the imposte thatsupports the trusses; Fig. e, a plan ot' portion of the roadway withfloor removed to expose the lateral braces.

In the drawings A represents the springer beams and B the key beam ofthearch of the truss; C,metal imposte movable on the abutments D to supportthe ends of the trusses; E, adjustable tie rods spanning the distancebetween the imposte; F, cross beams suspended from the arch of thetrusses by means of rods G; H, the joist and I the door thereon. Theends of the joist rest on the cross beams and on the abutments andtogether with the iloor form the roadway of the bridge; J, lateralbraces for the trusses secured to the extended extremities of thecross-beams; K, metal plates to cover the joints in the arch of thetrusses and form attachments for the top of lateral braces J.

Lateral movement of the roadway is prevented by braces L that areextended diag,- onally under the joist and are attached to thecross-beams and to the imposts.

The tie rods E are articulated or jointed at the crossdoeams and theyare secured thereon by means of side bolts M and bottom plate N.

The various rods and braces used in the construction of the bridge areprovided with the usual means of adjustment such as interposedturnbuckles or terminal nuts.

The imposts C are each formed with top wings O and P at right angles toeach other to form a seat for the extremity of the respective springerbeams A. Wings P are formed with bolt holes for the passage of bolts Qthat secure said beams thereon. Tapered openings R. for the passage ofthe tie rods are extended at an angle through the respective imposts.The inner end of said openings is widened to permit the tie rod to movelaterally up and down therein during its adjustment by means ot the nutson its opposite ends. Plates S cap the abutments and form a planesurface for the movement of the imposts that are loosely seated thereon.The vertical height of the imposts is sufcient to carry the springerbeams above the level of the roadway and out of con tact with theinfluences of the soil that would soon cause them to become decayed.

By means ofthe "n nts on the ends of the tie rods the correspondingimposts may be moved toward each other and the trusses contracted inlength. This adjustment of the trusses causes the ends ot' their membersto lit snugly together and distributes the weight on the roadway overthe cross-beams proportionately between the arch of the trusses and thetie rods. It the depending rods G are shortened by means of the nutsthereon to raise the cross-beams, the sag in the tie-rods will belessened and unless correspondinglyshortened the length ot the trusseswill be permitted to increase.

This manner otconstructing and adjusting the various members ofthebridge distributes the duty to be performed proportionately among thevarious members according to their strength, as the strut of the arch ofthe trusses is relieved by the tensile strength of the tie rods and inproportion to the amount of their sag.

Having fully described my improvements, what Iclaim as my invention, anddesire to secure by Letters Patent, is-

In a bridge, a metal impost movably seated on the abutment and formedwith aseat above the level of the roadway for an extremity of the archof the truss and containing a tapered opening at an angle therethroughfor the insertion of the tie rod.

WILLIAM S. BRELSFOARD.

W'itnesses:

CHARLES J. PARnisH, ROBERT S. CARR.

